NPI Portal NPI Lookup & Verification

Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. John Walter Irvine, MD

Internal Medicine Physician in Eureka, CA · enumerated 2006 · practices at Eureka Internal Medicine.

Data current as of Jul 11, 2026 · sourced from CMS NPPES

National Provider Identifier

1861598419

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Registry record

Entity type Individual (Type 1)
Name Dr. John Walter Irvine
Credential MD
Sex Male
Practice address 2280 Harrison Ave, Suite B, Eureka, CA, 95501
Phone (707) 443-9371
Enumeration date Sep 14, 2006
Last updated in NPPES Jun 28, 2011

Taxonomy & licenses

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License A23597 (CA) Primary
MD — Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

Other identifiers

Identifier Type State Issuer
00A235970 Medicaid CA —

What is an NPI number?

A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes — even if the provider moves or changes specialty.

Read the full guide → Validate an NPI →

Frequently asked questions

Is this the official NPI registry?
No. NPI Portal is a private site built on public CMS NPPES data. The official registry is npiregistry.cms.hhs.gov, operated by CMS.
What specialty is John Irvine?
John Irvine is registered in NPPES with the primary taxonomy of Internal Medicine Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

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Source: CMS NPPES (public data). Snapshot 2026-07-11. Provider record last updated 2011-06-28.